JP2005012114A - Method for manufacturing substrate with built-in passive element and the substrate with the built-in passive element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a substrate with a built-in passive element capable of obtaining a desired junction area for forming the passive element by forming an unevenness on the substrate without increasing a mask for forming the unevenness. <P>SOLUTION: A sensitive organic film 2 is formed on a substrate 1, and a via hole 3 for interconnection and the mask formed with a pattern of an unevenness 4 for forming a capacitor are employed, and the via hole 3 for interconnection and the unevenness 4 for forming the capacitor are simultaneously formed on the sensitive organic film 2 by a lithography. A wiring 7 and a capacitor 5 are formed in the via hole 3 for interconnection and the unevenness 4 for forming the capacitor formed in the sensitive organic film 2, respectively. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a passive element built-in substrate that incorporates passive elements such as resistors and capacitors, and a passive element built-in substrate.
[0002]
[Prior art]
A passive element built-in substrate in which passive elements such as resistors and capacitors are built in the same substrate is known. For example, the substrate with a built-in passive element shown in FIG. 6 has an interlayer film 22 formed on the substrate 21 and capacitors 24 and 25 formed on the interlayer film 22. In addition, a via hole 23 is formed in the interlayer film 22, and wiring connection is performed using the via hole 23. The capacitors 24 and 25 are constituted by lower electrodes 24a and 25a, insulating films 24b and 24c, and upper electrodes 24c and 25c, respectively.
[0003]
In such a passive element built-in substrate, when a plurality of capacitors 24 and 25 having different capacities are formed on the same substrate 21 as shown in FIG. 6, lower electrode 24a, which has a different area by changing the lithography mask pattern dimension. 25a is patterned. Thereby, capacitors 24 and 25 having different capacities are obtained.
[0004]
By the way, in recent years, as the miniaturization of elements progresses, it is essential to reduce the plane area of passive elements such as capacitors, and it is necessary to arrange large area capacitors for obtaining a large capacity on the same substrate. It has become difficult. Therefore, as shown in FIG. 7, an attempt has been made to secure the required capacitor capacity by forming irregularities 26 on the surface of the lower electrode 24a and increasing the effective area thereof.
[0005]
FIG. 8 shows a process for increasing the effective area of the lower electrode of the capacitor in the conventional method for manufacturing a substrate with built-in passive elements. As shown in FIG. 8, in the conventional method for manufacturing a substrate with built-in passive elements, first, exposure and development for forming a via hole 23 are performed on the interlayer film 22, and thereafter, irregularities 26 are formed on the surface of the lower electrode 24a. For resist application, exposure, development, dry etching, and resist removal.
[0006]
For example, Patent Document 1 describes a semiconductor device in which the surface area of a substrate is increased by similarly forming irregularities on the surface of the substrate, thereby increasing the bonding area while reducing the chip area. Also in the semiconductor device of this patent document 1, in order to form unevenness on the surface of the substrate, resist coating, exposure, development, dry etching, and resist removal are performed.
[0007]
[Patent Document 1]
JP 2002-368231 A (paragraphs 0006-0008, FIG. 6-7)
[0008]
[Problems to be solved by the invention]
Conventionally, as described above, when unevenness is provided for forming a passive element, it is necessary to use a resist mask for forming the unevenness. Therefore, five steps of a resist coating step, an exposure step, a development step, a dry etching step, and a resist removal step are added, and an increase in these steps is a problem.
[0009]
Therefore, in the present invention, a passive element built-in substrate capable of obtaining a desired junction area for forming a passive element by forming irregularities on the substrate without increasing the mask for forming the irregularities. It is an object to provide a manufacturing method and a substrate with built-in passive elements.
[0010]
[Means for Solving the Problems]
The method for manufacturing a substrate with a built-in passive element according to the present invention is a method for manufacturing a substrate with a built-in passive element, and includes a step of forming a photosensitive organic film on the substrate, a wiring connection via hole, and a pattern of unevenness for forming a passive element. A step of simultaneously forming via holes for wiring connection and irregularities for forming passive elements on the photosensitive organic film by lithography using the mask formed with the wiring via holes and irregularities for forming passive elements formed on the photosensitive organic film; Forming wirings and passive elements, respectively.
[0011]
According to the manufacturing method of the present invention, when a photosensitive organic film is formed on a substrate and a via hole for wiring connection is formed on the photosensitive organic film using a mask, in addition to the via hole pattern for wiring connection, a passive pattern is formed. Using the mask on which the element formation uneven pattern is formed, the wiring connection via hole and the passive element formation unevenness are simultaneously formed by lithography. Thereby, a desired junction area for forming a passive element can be obtained by this unevenness without increasing the mask for forming the unevenness for forming the passive element. And a passive element built-in substrate can be obtained by forming a wiring and a passive element in a wiring connection via hole and a passive element formation unevenness formed in this photosensitive organic film, respectively.
[0012]
The passive element-embedded substrate thus obtained has a photosensitive organic film on the substrate, and this photosensitive organic film has wiring connection via holes and passive element formation irregularities, and these wiring connection via holes and passive element formation Wiring and passive elements are respectively formed on the projections and depressions.
[0013]
Here, the photosensitive organic film is used on the substrate because the organic film has a small dielectric loss, has a certain dielectric constant, and can withstand heat treatment, so that the present invention can be used for a high-frequency module. It is because it becomes. In addition, since the organic film is photosensitive, the wiring connection via hole and the passive element formation unevenness can be simultaneously formed by lithography using one mask.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
FIG. 1 is a cross-sectional view showing a manufacturing process of a passive element built-in substrate according to the first embodiment of the present invention, and FIG. 2 is a flowchart showing details of the process of FIG.
[0015]
The substrate with a built-in passive element in the first embodiment of the present invention is a board 1 in which a plurality of capacitors 5 and 6 as passive elements are built, as shown in FIG. The substrate 1 is an organic substrate made of an organic material such as epoxy resin, but an inorganic substrate made of an inorganic material such as ceramic can also be used. A photosensitive organic film 2 is formed on the substrate 1. As shown in FIG. 1A, the capacitor 5 is provided on the capacitor forming irregularities 4 formed on the photosensitive organic film 2. The capacitor 6 is provided on the upper surface of the photosensitive organic film 2. As shown in FIG. 1B, the photosensitive organic film 2 is provided with a via hole 3 for wiring connection with the substrate 1.
[0016]
When manufacturing this substrate with built-in passive elements, first, as shown in FIGS. 1A and 2, a photosensitive organic film 2 is formed on the substrate 1 by a spin coating technique. The photosensitive organic film 2 is formed of a photosensitive material that can be patterned by a lithography technique. As the material of the photosensitive organic film 2, it is desirable to use photosensitive benzocyclobutene. Benzocyclobutene (hereinafter referred to as “BCB”) has low dielectric loss, has a certain dielectric constant, and can withstand heat treatment, so that a high-frequency module is formed using the substrate with a built-in passive element of the present invention. Are suitable.
[0017]
Next, using the mask (not shown) in which the pattern of the via hole 3 for wiring connection to the substrate 1 and the pattern of the capacitor forming unevenness 4 is formed, the via hole 3 and the capacitor forming unevenness 4 are formed by lithography. Patterning is performed. In the lithography process, the via hole 3 is usually formed through a development and baking process after exposure using an aligner or a stepper apparatus using a mask. In the manufacturing method according to the present embodiment, simultaneously with the formation of the via hole 3, The capacitor forming irregularities 4 are formed in the region where the capacitor 5 is to be formed.
[0018]
Thereafter, conductive films to be the lower electrodes 5a and 6a of the capacitors 5 and 6 are formed by a sputtering method or a chemical vapor deposition (CVD) method, and the insulating films 5b and 6b of the capacitors 5 and 6 are further formed. Conductive films to be the upper electrodes 5c and 6c of the capacitors 5 and 6 are formed. Then, after patterning using a capacitor formation mask (not shown), the capacitor is processed by wet or dry etching technology. As a result, capacitors 5 and 6 having different capacitances are formed on the photosensitive organic film 2 on the substrate 1 as shown in FIG. Thereafter, as shown in FIG. 1C, wiring 7 is formed in the via hole 3.
[0019]
As described above, according to the method for manufacturing a substrate with built-in passive elements in the present embodiment, for example, even if the planar areas of the capacitors 5 and 6 are the same, the lower electrode 5a and the upper electrode 5c of the capacitor 5 and the insulating film 5b. Is different from the junction area between the lower electrode 6a and the upper electrode 6c of the capacitor 6 and the insulating film 6b, so that capacitors 5 and 6 having different capacities can be realized. Further, it is not necessary to compensate for the reduction in the capacitor capacity accompanying the miniaturization of the element by reducing the thickness of the insulating film 6b or reducing the operating voltage, and it can be ensured by changing the pattern of the capacitor forming irregularities 4.
[0020]
At this time, in the manufacturing method according to the present embodiment, the pattern of the via hole 3 and the capacitor 5 are formed in the region for forming the wiring 7 with the substrate 1 without using a mask for forming the capacitor forming unevenness 4 separately. Since the via hole 3 and the capacitor forming unevenness 4 are simultaneously formed using one exposure mask in which the pattern of the capacitor forming unevenness 4 is laid out in the region to be formed, the conventionally used unevenness forming mask is used. Can be reduced. In addition, the conventional lithography process, dry etching process, and resist removal process for forming irregularities can be reduced. Further, the throughput of the manufacturing process can be shortened by reducing the number of steps.
[0021]
(Embodiment 2)
FIG. 3 is a sectional view showing a substrate with built-in passive elements according to the second embodiment of the present invention.
[0022]
As shown in FIG. 3, the passive element-embedded substrate in the second embodiment of the present invention is a capacitor forming unevenness in place of the capacitor 6 formed on the upper surface of the photosensitive organic film 2 in the first embodiment. A capacitor 8 is formed on 9. Similar to the capacitor 5, the capacitor 8 includes a lower electrode 8a, an insulating film 8b, and an upper electrode 8c. Other configurations are the same as those in the first embodiment.
[0023]
The bottom surface of the concave portion of the capacitor forming unevenness 4 reaches the substrate 1, whereas the capacitor forming unevenness 9 is formed to a depth up to the middle of the photosensitive organic film 2. In order to change the depth of the unevenness such as the capacitor forming unevenness 4 and the capacitor forming unevenness 9, for example, the exposure amount at the time of patterning in the lithography process for forming the unevenness is adjusted to the resolution of the large pattern. As a result, the exposure amount is insufficient for a small size pattern, and the pattern is formed only halfway through the photosensitive organic film 2.
[0024]
As described above, according to the manufacturing method of the present embodiment, capacitors 5 and 8 having different capacities can be realized even when the plane area is the same by changing the pattern depth of the capacitor forming irregularities 4 and 9. Is possible. Further, capacitors having different capacitances can be formed on the same substrate 1 by changing the size, shape, layout, number, etc., in addition to the depth of the uneven pattern in the capacitor formation region.
[0025]
(Embodiment 3)
FIG. 4 is a sectional view showing a substrate with built-in passive elements according to the third embodiment of the present invention.
[0026]
As shown in FIG. 4, the substrate with built-in passive element according to the third embodiment of the present invention includes a plurality of resistors 10 and 11 as passive elements. In the region where the resistor 10 is formed, the resistor forming unevenness 12 similar to the capacitor forming unevenness 4 is formed. The resistor 10 is provided on the resistor forming irregularities 12. The resistor 11 is provided on the photosensitive organic film 2. The method for forming the resistor forming irregularities 12 is the same as in the first embodiment.
[0027]
As shown in FIG. 4, even when a plurality of resistors 10 and 11 are formed as passive elements, the wiring 7 with the substrate 1 is formed without using a mask for forming the resistor forming irregularities 12 separately. The via hole 3 and the resistor forming unevenness 12 are formed using one exposure mask in which the pattern of the via hole 3 is formed in the region for forming the resistor and the pattern of the resistor forming unevenness 12 is formed in the region where the resistor 10 is formed. By forming them simultaneously, the same effect as in the first embodiment can be obtained.
[0028]
(Embodiment 4)
FIG. 5 is a sectional view showing a substrate with built-in passive elements according to the fourth embodiment of the present invention.
[0029]
As shown in FIG. 5, the passive element-embedded substrate according to the fourth embodiment of the present invention is formed with a resistor instead of the resistor 11 formed on the upper surface of the photosensitive organic film 2 in the third embodiment. A resistor 13 is formed on the projections and depressions 14. The bottom surface of the concave portion of the resistor forming unevenness 12 reaches the substrate 1, whereas the resistor forming unevenness 14 is formed to a depth halfway of the photosensitive organic film 2. The method of forming the resistor forming irregularities 12 and 14 having different depths is the same as in the second embodiment. Other configurations are the same as those in the third embodiment.
[0030]
As shown in FIG. 5, by changing the pattern depth of the resistor forming irregularities 12, 14, the resistor 10, 10 having different resistance values even if the plane area is the same as in the second embodiment. 13 can be realized.
[0031]
As described above, according to the manufacturing methods of the first to fourth embodiments of the present invention, via holes and passive element forming irregularities can be formed simultaneously using one exposure mask. At this time, by changing the size, shape, layout, number, depth, etc. of the irregularities for forming the passive elements without changing the plane area of the substrate, a desired junction area for forming the passive elements can be obtained. The size, shape, layout, number, depth, etc. of the irregularities for forming the passive element can be adjusted by changing the film thickness of the photosensitive organic film, the opening size of the mask, the number of openings, the opening shape, the opening layout, etc. .
[0032]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0033]
(1) A photosensitive organic film is formed on a substrate, and a wiring connection via hole and a passive element forming uneven pattern are formed on the photosensitive organic film by lithography using a mask on which a wiring connection via hole and passive element formation pattern are formed. By forming wirings and passive elements on the wiring connection via hole and passive element forming unevenness formed on the photosensitive organic film, respectively, by forming unevenness at the same time, without increasing the mask for forming the unevenness, In this case, the concave and convex portions for forming the passive element can be simultaneously formed on the substrate by using one mask. This makes it possible to obtain a desired junction area for forming passive elements on the same substrate, and incorporate various passive elements such as capacitors with different capacitances and resistors with different resistance values without changing the plane area. A passive element built-in substrate is obtained.
[0034]
(2) Since the unevenness for forming a passive element is formed using a single mask when forming a via hole, the conventional lithography process, dry etch process, and resist removal process for forming the unevenness can be reduced. Further, the throughput of the manufacturing process can be shortened by reducing the number of steps.
[0035]
(3) It is not necessary to compensate for the capacitor capacity reduction accompanying the miniaturization of the passive element by reducing the thickness of the insulating film or reducing the operating voltage, and can be ensured by changing the pattern of the capacitor forming unevenness.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a manufacturing process of a substrate with a built-in passive element according to a first embodiment of the present invention.
FIG. 2 is a flowchart showing details of the process of FIG.
FIG. 3 is a cross-sectional view showing a substrate with a built-in passive element in a second embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a substrate with a built-in passive element according to a third embodiment of the present invention.
FIG. 5 is a cross-sectional view showing a substrate with built-in passive elements according to a fourth embodiment of the present invention.
FIG. 6 is a cross-sectional view showing an example of a conventional substrate with built-in passive elements.
FIG. 7 is a cross-sectional view showing another example of a conventional substrate with built-in passive elements.
FIG. 8 is a flowchart showing a process for increasing an effective area of a lower electrode of a capacitor in a conventional method for manufacturing a substrate with built-in passive elements.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Substrate 2 Photosensitive organic film 3 Via hole 4, 9 Unevenness for capacitor formation 5, 6, 8 Capacitors 5a, 6a, 8a Upper electrodes 5b, 6b, 8b Insulating films 5c, 6c, 8c Lower electrode 7 Wirings 10, 11, 13 Resistors 12, 14 Concavities and convexities for forming resistors

Claims (3)

A method of manufacturing a substrate incorporating a passive element,
Forming a photosensitive organic film on the substrate;
Simultaneously forming the wiring connection via hole and the passive element formation unevenness on the photosensitive organic film by lithography using a mask in which a pattern of the wiring connection via hole and the passive element formation unevenness is formed;
Forming a wiring and a passive element in the wiring connection via hole and the passive element forming unevenness formed in the photosensitive organic film, respectively. A substrate containing a passive element,
Having a photosensitive organic film on the substrate;
This photosensitive organic film has via holes for wiring connection and irregularities for forming passive elements,
A passive element-embedded substrate in which wirings and passive elements are formed on the via holes for wiring connection and the irregularities for forming passive elements, respectively. The passive element-embedded substrate according to claim 2, wherein the photosensitive organic film is photosensitive benzocyclobutene.

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